Silicon (Si) is recognized as a promising anode material for next-generation lithium-ion batteries owing to its exceptionally high lithium storage capacity. Recently, micro-sized Si (micro-Si) based anodes have re-emerged as alternatives to nano-sized Si (nano-Si) owing to their higher tap density and reduced interfacial side reactions. Considerable efforts are devoted to addressing the rapid capacity decay caused by severe volume expansion, sluggish kinetics, and continuous accumulation of the solid electrolyte interphase. In this review, the primary failure mechanisms of micro-Si anodes is first analyzed and subsequently summarize recent advances in enhancing their structural and interfacial stability. The design of Si-containing materials (primarily Si/C composites and SiOx structures) that meet the current industrial requirements is discussed. Additionally, binder optimization and electrolyte exploration are analyzed. Finally, the potential application of advanced spectroscopic, electronic, and mechanical characterization techniques is explored, coupled with machine learning, in developing Si-based anodes. This review aims to comprehensively understand the rational design and in-depth analysis of next-generation micro-Si based lithium-ion batteries.

• Klíčová slova
• advanced characterization techniques, binder modifications, electrolyte designs, micro‐sized Si‐based anodes, structural designs,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Germanium, with a high theoretical capacity based on alloyed lithium and germanium (1384 mA h g-1 Li15Ge4), has stimulated tremendous research as a promising candidate anode material for lithium-ion batteries (LIBs). However, due to the alloying reaction of Li/Ge, the problems of inferior cycle life and massive volume expansion of germanium are equally obvious. Among all Ge-based materials, the unique layered 2D germanane (GeH and GeCH3) with a graphene-like structure, obtained by a chemical etching process from the Zintl phase CaGe2, could enable storage of large quantities of lithium between their interlayers. Besides, the layered structure has the merit of buffering the volume expansion due to the tunable interlayer spacing. In this work, the beyond theoretical capacities of 1637 mA h g-1 for GeH and 2048 mA h g-1 for GeCH3 were achieved in the initial lithiation reaction. Unfortunately, the dreadful capacity fading and electrode fracture happened during the subsequent electrochemical process. A solution, i.e. introducing single-wall carbon nanotubes (SWCNTs) into the structure of the electrodes, was found and further confirmed to improve their electrochemical performance. More noteworthy is the GeH/SWCNT flexible electrode, which exhibits a capacity of 1032.0 mA h g-1 at a high current density of 2000 mA g-1 and a remaining capacity of 653.6 mA h g-1 after 100 cycles at 500 mA g-1. After 100 cycles, the hybrid germanane/SWCNT electrodes maintained good integrity without visible fractures. These results indicate that introducing SWCNTs into germanane effectively improves the electrochemical performance and maintains the integrity of the electrodes for LIBs.

• Publikační typ
• časopisecké články MeSH